1 Pet rocks, toe socks, and mood rings are fads that teens have embraced from the late twentieth century into the twenty-first century. You may not have heard of pet rocks. However, toe socks and mood rings are probably familiar. Did you know that all three first appeared in the 1970s?2 Millions of pet rocks were sold in the mid-seventies. They first appeared in August 1975. The creator, Gary Dahl, made millions of dollars from the idea of putting a rock in a small box with air holes and calling it a pet. Can you believe it? Kids loved those things! The pet rock product came with a straw nest and a booklet of training tips. The proud owner could teach a pet rock how to roll over and play dead! A lot of the appeal was in the humor surrounding the idea of a pet rock. Dahl's novel idea was such a big hit that he was invited to appear on The Tonight Show! The original pet rock was not called "original." It also did not have plastic wiggle eyes glued onto it. Those were knock-offs created to take advantage of the pet rock craze. Can you imagine getting rich by selling something that you found just lying around?3 A few years ago, pet rocks tried to make a comeback. However, today's youth seem to have more common sense. They are less willing to throw away money on an item that they can pick up from the ground for free.